| 摘要 |
PURPOSE:To obtain a replica plate which has mass-productivity and which is excellent in birefringence on its outer periphery by a method wherein a mold is opened by being deformed with injection molding pressure and, after the finish of injection, compressed by the elastic repulsive forces of tie bars and of a movable mold plate. CONSTITUTION:A range finder 6 to measure the opening of a stationary mold 3 and a movable mold 4 is fixed with a jig 7 on a stationary mold plate 1 so as to come into contact with a receiving jig 8 on a movable mold plate 2 in order to display the opening of molds in unit of mum on a digital display 9. After the reading on the display 9 is reset to zero at mold closing and, in addition, mold closing pressure is controlled in such a manner that the opening of molds becomes 8mum, which corresponds to the shrinkage of a replica plate made of polycarbonate resin, by yielding to the mold closing pressure, the injection compression molding utilizing the elastic repulsive forces of tie bars 5 and of movable mold plate 2 is performed. |
